JP2001173949A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the combustion state of a burner in a stable state, even if a demanded combustion amount fluctuates widely as the function of a zero governor is effectively utilized. SOLUTION: A combustion device is provided with a whole primary premixture type burner 3, and a zero governor 14 installed in a fuel feed passage 11, for feeding fuel and maintaining a fuel feed pressure, at a spot situated downstream of the installation spot, in an atmosphere pressure. The combustion device is constituted, such that a control means H controls a fuel feed amount control means N with a region where a combustion amount demanded in combustion of the burner 3 is low is more increased in passage resistance of fuel than a region, where it is high and controls a combustion air feed amount control means M, such that a region where a combustion amount demanded in combustion of the burner 3 is low is further increased in passage resistance of combustion air than in a region where it is high, and the number of revolutions of a ventilation fan 4 is controlled, such that a ventilation amount is adjusted to a proper value equivalent to a combustion amount, demanded in combustion of the burner 3, despite of control by the air feed amount regulating means M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-primary premix type burner, and ventilation of combustion air to the burner through an air passage, and the supply of fuel supplied with the ventilation to the combustion air. A ventilation fan that is mixed with and supplied to the ventilation path so that suction force acts by the ventilation action of the ventilation fan, a fuel supply path for supplying fuel, and a fuel supply path, A zero governor that maintains the fuel supply pressure downstream of the installation location at atmospheric pressure and control means for controlling the combustion of the burner are provided, and the control means reduces the amount of combustion required in the combustion of the burner. The present invention relates to a combustion device configured to adjust the number of revolutions of the ventilation fan so as to provide a corresponding ventilation amount.

[0002]

2. Description of the Related Art In a combustion apparatus as described above, a fuel supply pressure downstream of the installation location is maintained at an atmospheric pressure by a zero governor, and the atmospheric pressure and a negative pressure generated in a ventilation path by the operation of a ventilation fan. Fuel is supplied to the ventilation path by the pressure difference, and the amount of fuel supplied to the ventilation path and the amount of combustion air supplied to the ventilation path are adjusted by adjusting the number of revolutions of the ventilation fan. No.). Then, in such a combustion device, as shown in FIG. 12, the combustion amount required in the combustion of the burner, that is, the input of the burner is obtained, and the rotation speed of the ventilation fan is set so as to be on the steady fan control line Lt. Is controlled.

[0003]

However, in the prior art, when the maximum input required for the burner is determined, a fan having a capacity corresponding to this is selected and the system is constructed. Has the following disadvantages because the fan speed can only be changed on the steady fan control line Lt. That is, the input adjustment range is limited to the fan rotation speed adjustment range. In other words, if the ratio of the maximum input to the minimum input required for the burner becomes large, for example, about 15: 1,
Although the fan rotation speed adjustment range must be set to 15: 1, it is technically difficult to widen the rotation speed adjustment range in this way. Therefore, there is a practical problem that the input adjustment range is narrowed due to the restriction of the fan speed control. Further, even if the problem of the rotational speed control is solved, the steady fan control line Lt
Since it is only possible to change the fan rotation speed above, when controlling from the maximum input to the minimum input, or conversely, when controlling from the minimum input to the maximum input,
There is a problem that there is a limitation on the responsiveness of the fan rotation speed control, so that it cannot be changed quickly.

In a conventional combustion apparatus, a fixed orifice is usually provided at a position downstream of the zero governor in the fuel supply path in order to stabilize the amount of fuel supplied to the ventilation path. The fixed orifice is set so that the required flow rate can be obtained when the input required in combustion of the burner is maximum. At this time, when the ratio between the required maximum input and the minimum input is small, the control can be performed without any problem. However, when the ratio is increased, the following problem occurs. That is, if the fuel flow rate when the required input is small is smaller than the minimum leakage amount of the zero governor, the fuel flow rate cannot be controlled.
That is, not only cannot the fuel supply amount be adjusted to the required fuel supply amount, but also the air ratio (the ratio of the actual air amount to the theoretical air amount) required by the burner cannot be adjusted, resulting in inconvenience such as poor combustion.

The present invention has been made in view of such a point, and an object of the present invention is to effectively utilize the function of the zero governor while maintaining the combustion state of the burner in the entire combustion amount required for the combustion of the burner. Is to provide a combustion device capable of maintaining a stable state.

[0006]

According to the first aspect of the present invention, there is provided a suction unit for sucking combustion air into a ventilation passage, which reduces a passage resistance of the combustion air. By changing, the combustion air supply amount adjusting means for adjusting the combustion air supply amount to the ventilation path, and provided at a position downstream of the zero governor in the fuel supply path, by changing the fuel passage resistance, Fuel supply amount adjusting means for adjusting the amount of fuel supplied to the ventilation path is provided, and the control means makes the passage resistance of the fuel larger in a region where the amount of combustion required for burning the burner is smaller than in a region where the amount of combustion is larger. The fuel supply amount adjusting means is adjusted so that the combustion air supply resistance is higher in a region where the amount of combustion required in combustion of the burner is smaller than in a region where the amount of combustion required is larger. And controlling the number of rotations of the ventilation fan so as to obtain an appropriate ventilation amount according to the combustion amount required in the combustion of the burner regardless of the adjustment of the combustion air supply amount adjusting means. I have.

Therefore, the amount of fuel supplied to the ventilation path by the fuel supply amount adjusting means and the amount of combustion air supplied to the ventilation path by the combustion air supply amount adjusting means are determined according to the amount of combustion required in the combustion of the burner. Each of the amounts can be in a plurality of adjustment states, and in each of the plurality of adjustment states, the number of rotations of the ventilation fan is controlled so as to provide an appropriate ventilation amount corresponding to a combustion amount required in combustion of the burner. be able to. That is, for example, in a state where the ventilation fan is operated at the same rotation speed, by changing the adjustment state of the fuel supply amount adjustment unit and the combustion air supply amount adjustment unit, the combustion amount in the burner combustion, that is, the burner input It is possible to quickly adjust to the required combustion amount without adjusting the rotation speed of the ventilation fan in a large range even if the required ratio of the maximum input to the minimum input is large. Became.

Further, the fuel supply amount adjusting means increases the fuel passage resistance in a region where the amount of combustion required for burning the burner is smaller than in a region where the amount of combustion required is large.
Since the fuel flow rate in the fuel supply path becomes a flow rate corresponding to the required combustion amount, the fuel supply pressure on the downstream side of the installation location is maintained at the atmospheric pressure with the zero governor, and the combustion required in the burner combustion is performed. By controlling the ventilation fan at the rotation speed corresponding to the amount, it is possible to obtain a fuel supply amount corresponding to the combustion amount required in the combustion of the burner, and it is possible to effectively utilize the function of the zero governor. Therefore, while effectively utilizing the function of the zero governor, the combustion state of the burner is maintained in a stable state without increasing the range for adjusting the rotation speed of the ventilation fan over the entire combustion amount required in the combustion of the burner. be able to.

According to the second aspect of the present invention, the combustion air supply amount adjusting means is configured to adjust the passage area of the suction section. That is, by adjusting the passage area of the suction unit, the passage resistance of the combustion air is changed, and the passage area of the suction unit is adjusted with a simple configuration using a movable damper or the like. Since it can be performed, by adopting such a mode of adjusting the passage area of the suction section, the combustion air supply amount adjusting means can be simplified in configuration.

According to the third aspect of the present invention, the fuel supply amount adjusting means is configured to adjust the passage area of the fuel supply passage. That is, the passage resistance of the fuel is changed by adjusting the passage area of the fuel supply passage, and the passage area of the fuel supply passage can be adjusted with a simple configuration using a proportional valve or the like. Therefore, by adopting such a mode of adjusting the passage area of the fuel supply passage, the fuel supply amount adjusting means can be simplified in configuration.

According to the fourth aspect of the present invention, the fuel supply path is branched into a plurality of fuel supply path portions and connected to the ventilation path, and the fuel supply amount adjusting means includes the plurality of fuel supply paths. An electromagnetic opening / closing valve is provided corresponding to all or a part of the portion and opens and closes the installed fuel supply path portion, and the passage area of the fuel supply path is adjusted by opening / closing the electromagnetic opening / closing valve. Is configured. That is, as described in claim 3, in order to adjust the passage area of the fuel supply passage, a mode is adopted in which all or a part of the plurality of fuel supply passage portions are opened and closed by an electromagnetic on-off valve, and Since the solenoid on-off valve is inexpensive compared to the proportional valve, a simple and inexpensive configuration of the fuel supply amount adjusting means is adopted by adopting the form in which the passage area of the fuel supply path is adjusted using the solenoid on-off valve. Can be

According to the invention described in claim 5, the combustion air supply amount adjusting means and the fuel supply amount adjusting means are integrally formed. Therefore, instead of separately adjusting the fuel supply amount to the ventilation passage and the combustion air supply amount to the ventilation passage, both of them can be adjusted at once, and the adjustment control can be easily performed.

According to the invention described in claim 6, the control means controls the burner in accordance with the combustion amount required for burning the burner.
The target mixture ratio of fuel and combustion air in the ventilation passage is configured to be different. That is, since the target mixture ratio can be set according to the amount of combustion required in the combustion of the burner, for example, the surface temperature of the burner tends to increase in a region where the amount of combustion is small. In a region where the amount is small, the combustion state of the burner can be stabilized while taking into account the combustion characteristics of the burner, such as setting the target air ratio (the ratio of the target actual air amount to the theoretical air amount) high. State.

According to the seventh aspect of the present invention, since the fuel and the combustion air are mixed on the upstream side in the fuel supply direction with respect to the ventilation fan, the fuel supply direction is more than in the ventilation fan. The fuel and the combustion air can be supplied to the burner by the ventilation fan in a state where the fuel and the combustion air are surely mixed as compared with the case where the fuel and the combustion air are mixed on the downstream side of the burner. It is possible to reliably maintain a stable state.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which a combustion device according to the present invention is applied to a hot water supply device will be described with reference to the drawings. As shown in FIG. 1, the hot water supply apparatus includes a hot water supply unit K for heating supplied water to supply hot water to a hot water tap (not shown), a control unit H as control means for controlling the operation of the hot water supply unit K, A remote control operation unit R for instructing the control unit H to send operation information is provided.

The hot water supply unit K comprises a heat exchanger 2 for water heating provided in the combustion chamber 1, a gas-fired all-primary premix burner 3 for heating the heat exchanger 2, and the like. ,
A ventilation fan 4 is provided from the upstream side of the burner 3, through which the combustion air is passed through the air passage 7, and in accordance with the ventilation, the supplied fuel gas is mixed with the combustion air and supplied. The combustion surface of the burner 3 is composed of a metal plate 3a. The heat exchanger 2 has an inlet 5 for supplying water from a household water supply, for example, and a tap 6 for discharging hot water after heating. Are respectively connected to the water inlet channel 5, and a water flow sensor 8 for detecting a water flow amount to the heat exchanger 2, and an input water temperature thermistor for detecting the temperature of water supplied through the water inlet channel 5, in order from the upstream side. 9 are provided.
The tapping path 6 is provided with a tapping temperature thermistor 10 for detecting the temperature of tap water from a tap tap (not shown).

A fuel supply path 11 for supplying fuel to the ventilation path 7 is connected to the ventilation path 7 so that a suction force is exerted by the ventilation action of the ventilation fan 4, and is provided in the fuel supply direction more than the ventilation fan 4. On the upstream side, fuel and combustion air are mixed. That is, as the rotation speed of the ventilation fan 4 increases, the amount of fuel gas supplied to the ventilation path 7 increases. The fuel supply passage 11 has an electromagnetically operated safety valve 12 and a main valve 1 that intermittently supply fuel from the upstream side in the fuel supply direction.
3. Zero governor 14 for maintaining the fuel supply pressure downstream of the installation location at atmospheric pressure, and fuel supply amount adjusting means N for adjusting the fuel supply amount to ventilation passage 7 by changing the fuel passage resistance. Each of the fuel regulating valves 15 is provided. That is, the fuel adjusting valve 15 is provided in the fuel supply passage 11 on the downstream side of the zero governor 14 in the fuel supply direction and in series with the zero governor 14.

Suction unit 2 for sucking combustion air into ventilation passage 7
5 is provided with a movable damper 24 as a combustion air supply amount adjusting means M for adjusting the combustion air supply amount to the ventilation passage 7 by changing the passage resistance of the combustion air. The movable damper 24 is connected to the suction unit 25.
The passage area of the opening is adjusted in two stages, large and small, so that the amount of combustion air supplied to the ventilation passage 7 is adjusted.

An igniter 16 for performing an ignition operation for the burner 3 and a frame rod 17 for detecting whether or not the burner 3 is ignited are provided near the burner 3 respectively. The frame rod 17
Detects the value of the current flowing through the combustion flame and the metal plate 3a, and is configured so that the detected current value changes according to the combustion state of the burner 3.

Referring to the zero governor 14, as shown in FIG. 2, a valve body 14a for adjusting the opening degree of the gas passage, a diaphragm 14b for receiving a pressure difference between the atmospheric pressure Pt and the zero governor outlet pressure P2, and a valve body 14a. And a spring 14c supporting the diaphragm 14b and the spring 1
It comprises an adjusting mechanism 14d for adjusting 4c. For example, when the zero governor inlet pressure P1 fluctuates upward, the zero governor outlet pressure P2 also fluctuates upward along with the pressure fluctuation. However, the valve body 14a moves along with the zero governor outlet pressure P2 pressure fluctuation. Moves downward to cause the zero governor outlet pressure P2 to fluctuate downward, thereby adjusting the zero governor outlet pressure P2 to the atmospheric pressure Pt. Further, when the atmospheric pressure Pt fluctuates upward, the valve body 14a moves upward in accordance with the pressure fluctuation, and the zero governor outlet pressure P2 is adjusted to the atmospheric pressure Pt fluctuating upward. In this way, even when the primary fuel supply pressure P1 to the zero governor 14 and the atmospheric pressure Pt fluctuate, the zero governor outlet pressure P2 remains at the atmospheric pressure P2.
It is adjusted to be t.

As shown in FIG. 3, the fuel adjusting valve 15 is rotated by a stepping motor 15a and a stepping motor 15a to adjust the opening degree of the gas passage, that is, the passage area. 15b, the passage area of the fuel supply passage 11 is adjusted in two stages, large and small, so that the fuel supply amount to the ventilation passage 7 is adjusted.

The remote control operation section R includes an operation switch 18 for instructing start / stop of the operation of the hot water supply section K, a temperature setting switch 20 for changing and setting a target temperature for tapping, a tapping temperature and a target temperature for tapping. The display unit 21 includes an operation lamp 22, an operation lamp 22 for displaying the operation state, a combustion lamp 23 for indicating that the burner 3 is in the combustion state, and the like.

The controller H is provided with a microcomputer, and executes combustion control based on an operation command of the remote controller R during tapping so that the tapping temperature becomes the target tapping temperature. Specifically, the operation switch 18
After the water supply amount detected by the water flow amount sensor 8 exceeds the set water amount due to the opening operation of the hot water tap (not shown) after the operation state is set in accordance with the ON operation of, the ventilation operation by the ventilation fan 4 is performed. Starting, the safety valve 12 and the main valve 13 are opened to adjust the rotation speed of the ventilation fan 4 so that the amount of gas for ignition is adjusted, and the igniter 14 ignites the burner 3 and the flame rod 17 An ignition process for confirming the ignition of the burner 3 is executed.

The tap water temperature is determined based on the detection information of the tap water temperature thermistor 9, the tap water temperature thermistor 10, and the flow rate sensor 8, and the information of the tap water target temperature set by the temperature setting switch 20. The feedforward control is performed to adjust the ventilation amount of the ventilation fan 4 so that the amount of combustion required to reach the hot water tapping target temperature is achieved, and the feedforward control is performed in accordance with the deviation between the detected temperature of the hot water temperature thermistor 10 and the hot water tapping target temperature. Then, a combustion amount control process for executing feedback control for finely adjusting the ventilation amount of the ventilation fan 4 is executed. In this way, the water from the water inlet channel 5 is heated by the heat exchanger 2, and hot water having a target temperature for hot water is discharged from a hot water tap (not shown).

The combustion amount control process will be described in further detail. The detection information of each of the incoming water temperature thermistor 9, the outgoing water temperature thermistor 10, and the water flow rate sensor 8, and the target temperature for hot water set by the temperature setting switch 20 , The amount of combustion required for setting the tapping temperature to the tapping target temperature, that is, the input of the burner 3 is calculated. Then, the fuel control valve 15 is adjusted so that the passage resistance of the fuel is higher in the region where the calculated input is smaller than in the region where the input is smaller, and the combustion is performed in the region where the calculated input is smaller than the larger region. The movable damper 24 is adjusted so that the passage resistance of the working air is increased.
The feedforward control is executed by controlling the rotation speed of the ventilation fan 4 so as to be on the fan control line L1 or the second fan control line L2. In addition,
In each stage of the first fan control line L1 and the second fan control line L2, the target mixture ratio of fuel and combustion air in the ventilation passage 7 is kept constant.

The first fan control line L1 and the second fan control line L1
Switching of the fan control line between the fan control line L2 and the fan control line L2 will be described. As shown by the dotted line in FIG.
When the rotation speed of the ventilation fan 4 is controlled above,
When the input becomes larger than the maximum input of the first fan control line L1, the fan control line is switched to be controlled on the second fan control line L2. Further, when the rotation speed of the ventilation fan 4 is controlled on the second fan control line L2, if the input becomes smaller than the minimum input of the second fan control line L2, the control is performed on the first fan control line L1. Switch the fan control line to

That is, as shown in FIGS. 4 and 5, when the obtained input is in a small region, the fuel adjusting valve 15 adjusts the passage area of the fuel supply passage 11 to be small, and the movable damper 24 By suction unit 2
5 so that the passage area of the opening is small.
The rotation speed of the ventilation fan 4 is controlled so as to be on the fan control line L1. Further, when the obtained input is in a large area, the fuel control valve 15 adjusts the passage area of the fuel supply passage 11 to be large, and the movable damper 24 increases the passage area of the opening of the suction part 25. The rotation speed of the ventilation fan 4 is controlled so as to be on the second fan control line L2.

In this manner, the amount of fuel supplied to the ventilation path 7 and the amount of combustion air supplied to the ventilation path 7 are adjusted in accordance with the amount of combustion required in the combustion of the burner 3, and the number of rotations of the ventilation fan 4 is adjusted in a plurality of steps. Thus, even if the amount of combustion required in the combustion of the burner 3 greatly fluctuates, the function of the zero governor 14 can be effectively utilized and the burner 3 can be adjusted without increasing the adjustment range of the rotation speed of the ventilation fan 4. Can be maintained in a stable combustion state.

The control operation of the control section H will be described with reference to the flowchart of FIG. First, in a state where the operation switch 18 of the remote control operation unit R is turned on and the hot water supply device is set to the operation state, the water flow rate detected by the water flow rate sensor 8 with the opening operation of the hot water tap (not shown). When exceeds the set water amount, the ignition process of the burner 3 and the combustion amount control process are sequentially performed (steps 1 to 4). That is, when the combustion of the burner 3 is stopped, the ventilation operation by the ventilation fan 4 is started, and the rotation speed of the ventilation fan 4 is adjusted so that the safety valve 12 and the main valve 13 are opened and the ignition gas amount is reached. The ignition of the burner 3 is performed by the igniter 14, and the ignition of the burner 3 is confirmed by the frame rod 17.

Thereafter, the tap water temperature is determined based on the detection information of the inlet water temperature thermistor 9, the tap water temperature thermistor 10, the flow rate sensor 8, and the information of the tap water target temperature set by the temperature setting switch 20. The amount of combustion required to reach the hot water target temperature, that is, the input of the burner 3 is calculated. When the calculated input is in a small area, the fuel adjustment valve 15 adjusts the passage area of the fuel supply passage 11 to be small, and the movable damper 24 reduces the passage area of the opening of the suction unit 25. Then, the rotation speed of the ventilation fan 4 is controlled so as to be on the first fan control line L1. Further, when the obtained input is in a large area, the fuel control valve 15 adjusts the passage area of the fuel supply passage 11 to be large, and the movable damper 24 increases the passage area of the opening of the suction part 25. The rotation speed of the ventilation fan 4 is controlled so as to be on the second fan control line L2. In this way, the feedforward control is performed, and the feedback control for finely adjusting the ventilation amount of the ventilation fan 4 according to the deviation between the detected temperature of the tapping temperature thermistor 10 and the tapping target temperature is executed.

In this way, the ignition process and the combustion amount control process of the burner 3 are executed until the amount of water passing through the heat exchanger 2 becomes less than the set amount or the operation switch 18 is turned off. That is, when the amount of water flowing to the heat exchanger 2 becomes less than the set amount or the operation switch 18 is turned off, if the burner 3 is burning, the safety valve 12 and the main valve 13 are closed, and the burner 3 is closed. A burner combustion stop process for stopping the combustion of No. 3 is performed (step 5).

[Other Embodiments] (1) In the above embodiment, the fuel adjusting valve 15 for adjusting the passage area of the fuel supply passage 11 is used as the fuel supply amount adjusting means N.
A movable damper 24 for adjusting the passage area of the opening of the suction portion 25 is provided as the combustion air supply amount adjusting means M. The fuel supply amount adjusting means N and the combustion air supply amount adjusting means M are provided. Is not limited to this, and various configurations can be applied, and the configuration may be as follows. That is, as shown in FIG. 7, the fuel supply passage 11 is branched into a first fuel supply passage portion 11a and a second fuel supply passage portion 11b and connected to the ventilation passage 7, and the fuel supply amount adjusting means N An electromagnetic opening / closing valve 26 is provided corresponding to one fuel supply passage 11a and opens and closes the first fuel supply passage portion 11a. The passage area of the fuel supply passage 11 is adjusted by opening and closing the electromagnetic opening / closing valve 26. It is configured as follows. In the combustion amount control process, when the calculated input is in a small range, the electromagnetic on-off valve 26 is closed, and when the calculated input is in a large range, the electromagnetic on-off valve 26 is opened, and the ventilation The amount of fuel supplied to the road 7 is adjusted. Note that the movable damper 24 as the combustion air supply amount adjusting means M is the same as that in the above-described embodiment, and a description thereof will be omitted.

As described above, while the fuel supply passage 11 is branched into a plurality of fuel supply passage portions and connected to the ventilation passage 7, the electromagnetic opening / closing valve 26 is provided to constitute the fuel supply amount adjusting means N. The number of branches of the fuel supply path portion can be variously changed in accordance with the number of stages in which the fuel supply path is changed, and the solenoid on-off valve 26 can be provided and implemented in some of the fuel supply path sections. The electromagnetic on / off valve 2 is provided in a portion, for example, while the electromagnetic on / off valve 26 to be opened / closed is selected.
6 can be variously changed in the installation mode and the opening / closing control mode. Incidentally, the cross-sectional area of each fuel supply path section may be the same or different, and the plurality of fuel supply path sections themselves can be variously changed.

Instead of the configuration shown in FIG. 7, the following configuration may be adopted. That is, as shown in FIG. 8, the fuel supply path 11 is divided into the first fuel supply path 11c and the second fuel supply path 11c.
d, is connected to the ventilation path 7, and is provided with an electromagnetic on-off valve 27 for opening and closing the first fuel supply path 11c.
The fuel supply amount adjusting means N is configured in the same manner as in FIG. Further, a suction unit 25 for sucking the combustion air into the ventilation passage 7 includes a first suction unit 25a and a second suction unit 25b, and the second suction unit 2 serves as a combustion air supply amount adjusting unit M.
A movable damper 28 for opening and closing 5b is provided. In the combustion amount control process, when the calculated input is in a small range, the electromagnetic on-off valve 27 is closed, and the movable damper 28 is closed. The open / close valve 27 is opened and the movable damper 28 is opened, so that the amount of fuel supplied to the ventilation path 7 and the amount of combustion air supplied are adjusted.

Instead of the configuration shown in FIG. 8, the following configuration may be adopted. That is, as shown in FIG. 9, the fuel supply path 11 is connected to the ventilation path 7, and the fuel supply path 11 is provided with a fuel for adjusting the fuel supply amount to the ventilation path 7 by changing the fuel passage resistance. A fuel adjusting valve 15a is provided as a supply amount adjusting means N, and a suction unit 25 for sucking combustion air into the ventilation path 7 includes a first suction unit 25a 'and a second suction unit 25b'. Supply amount adjusting means M
Movable damper 28 for opening and closing the second suction part 25b '
a may be provided. The fuel control valve 15a
Is similar to that of the above-described embodiment shown in FIGS. 1 and 3, and a detailed description thereof will be omitted.
In the combustion amount control process, when the obtained input is in a small area, the fuel adjustment valve 15a adjusts the passage area of the fuel supply passage 11 to be small, and the movable damper 28a is closed. When the obtained input is in the large range, the fuel control valve 1
5a, the passage area of the fuel supply passage 11 is adjusted to be large, and the movable damper 28a is opened to adjust the fuel supply amount to the ventilation passage 7 and the combustion air supply amount.

Instead of the configuration shown in FIG. 9, the following configuration may be adopted. That is, as shown in FIG. 10, the needle member 29 as the fuel supply amount adjusting means N for adjusting the passage area of the opening of the fuel supply passage 11 to the ventilation passage 7 and the passage area of the opening of the suction unit 25 are reduced. The adjustment member 30 as the combustion air supply amount adjusting means M for adjusting the fuel supply amount.
It is integrally formed as a combustion air supply amount adjusting mechanism.
In the combustion amount control process, when the obtained input is in a small area, the ventilation path 7 of the fuel supply path 11
The fuel supply amount / combustion air supply amount adjustment mechanism is adjusted so as to reduce the passage area of the opening to the opening and the passage area of the opening of the suction unit 25, that is, to move the passage area to the left in FIG. I do. Further, when the obtained input is in a large area, the ventilation path 7 of the fuel supply path 11
The fuel supply amount / combustion air supply amount adjustment mechanism is adjusted so that the passage area of the opening to the air inlet and the passage area of the opening of the suction unit 25 are increased, that is, moved to the right in FIG. I do. Thus, the fuel supply amount and the combustion air supply amount to the ventilation passage 7 can be adjusted only by adjusting the fuel supply amount / combustion air supply amount adjustment mechanism.

Instead of the configuration shown in FIG. 10, the following configuration may be adopted. That is, as shown in FIG. 11, the fuel supply path 11 is branched into a first fuel supply path 11f and a second fuel supply path 11g, connected to the ventilation path 7, and further, the combustion air is sucked into the ventilation path 7. The suction unit 25 is the first suction unit 2
5c and a second suction unit 25d. The movable fuel damper 31 for opening and closing the opening of the first fuel supply path to the ventilation path 7 as the fuel supply amount adjusting means N
A combustion air adjustment movable damper 32 that opens and closes the opening of the first suction unit is integrally formed as a fuel supply amount / combustion air supply amount adjustment mechanism. In other words, the fuel supply
The combustion air supply amount adjusting mechanism is configured such that the fuel adjustment movable damper 31 and the combustion air movable damper 32 are integrally moved, and the opening of the first fuel supply passage 11f to the ventilation passage 7 and the first suction unit are provided. A closed state that closes both openings of 25c;
The opening of the first fuel supply passage 11f to the ventilation passage 7 and the first
The opening of both the openings of the suction section 25c is adjusted to an open state, so that the amount of fuel supplied to the ventilation passage 7 and the amount of combustion air supplied are adjusted. In the combustion amount control process, when the obtained input is in a small range, the fuel supply amount / combustion air supply amount adjustment mechanism is set to the first position.
Both the opening of the fuel supply passage 11f to the ventilation passage 7 and the opening of the first suction unit 25c are closed so that the fuel supply amount and the combustion air supply amount are in a region where the obtained input is large. The adjustment mechanism is connected to the first fuel supply path 11
The opening of both the opening to the ventilation path 7 and the opening of the first suction unit 25c is opened.

(2) In the above embodiment, the mixing ratio between the fuel and the combustion air in the ventilation passage 7 is determined by the first fan control line L1 or the second fan control line L1.
Although the rotation speed of the ventilation fan 4 is controlled in two stages so as to be higher than 2, the control of the rotation speed of the ventilation fan 4 is not limited to two stages and may be three or more stages. Then, for example, when the rotation speed of the ventilation fan 4 is controlled in three steps, the adjustment by the fuel adjustment valve 15 and the movable damper 24 is adjusted in three steps.
May be the same as the number of steps in the control of the number of revolutions by the fuel adjustment valve 15 and the movable damper 24.

(3) In the above embodiment, the number of revolutions of the ventilation fan 4 is controlled in two stages, and the target mixture ratio of fuel and combustion air in the ventilation passage 7 is controlled to be constant in each stage. In each stage, a different target mixture ratio may be set. For example, in the first fan control line L1 of FIG. 5, the target air ratio may be increased only in a region where the input is small. This is an effective means for avoiding a burner temperature rise during a small input. Specifically, the passage area of the fuel adjustment valve 15 shown in the above embodiment can be adjusted in three stages, and the opening degree of the fuel adjustment valve 15 can be adjusted to three stages in the first fan control line L1 in FIG. At the time of an input larger than the small input, the opening of the fuel adjusting valve 15 is set to the second-stage opening.
Then, in the second fan control line L2 in FIG. 5, the opening of the fuel adjusting valve 15 is set to the maximum opening of the first stage. In this case, the adjustment of the opening degree of the movable damper 24 is a two-step adjustment of large and small, as in the above embodiment. Alternatively, conversely, the movable damper 24 can adjust the passage area of the opening of the suction part 25 in three stages, and the first damper 24 shown in FIG.
In the fan control line L1, the opening of the possible damper 24 is set to the second opening when the input is small, and the opening of the movable damper 24 is set to the minimum aperture in the third opening when the input is larger than the small input. . Then, the second fan control line L of FIG.
In 2, the opening of the movable damper 24 may be set to the maximum opening of the first stage. In this case, the adjustment of the opening of the fuel adjustment valve 15 is performed in the same manner as in the above-described embodiment.
This is a step adjustment.

(4) In the above embodiment, an example is shown in which the combustion device according to the present invention is applied to a hot water supply device, but it is also applicable to various other devices such as a heating device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater.

FIG. 2 is a configuration diagram of a zero governor.

FIG. 3 is a configuration diagram of a fuel regulating valve.

FIG. 4 is a diagram showing an adjustment state of a fuel adjustment valve and a movable damper.

FIG. 5 is a diagram showing a relationship between a rotation speed of a ventilation fan and an input of a burner.

FIG. 6 is a diagram showing a control operation of a control unit.

FIG. 7 is a diagram showing a main part of a hot water supply device according to another embodiment.

FIG. 8 is a diagram showing a main part of a hot water supply device according to another embodiment.

FIG. 9 is a diagram showing a main part of a hot water supply device according to another embodiment.

FIG. 10 is a diagram showing a main part of a hot water supply device according to another embodiment.

FIG. 11 is a diagram showing a main part of a hot water supply device according to another embodiment.

FIG. 12 is a diagram showing the relationship between the number of rotations of a ventilation fan and the input of a burner in the related art.

[Explanation of symbols]

 Reference Signs List 3 Burner 4 Ventilation fan 7 Ventilation path 11 Fuel supply path 11a, 11b Fuel supply path part 11c, 11d Fuel supply path part 14 Zero governor 25 Suction unit 26, 27 Electromagnetic on-off valve H Control means M Combustion air supply amount adjusting means N Fuel Supply adjustment means

Continued on the front page (72) Yoshikatsu Ishikawa 1-1-52, Minami-shioka, Minato-ku, Osaka-shi, Osaka Prefecture Harman Co., Ltd. (72) Keiji Yokoyama 1-1-52, Minami-shioka, Minato-shi, Minato-ku, Osaka, Osaka Stock F-term in the company Harman (reference) 3K003 AA01 AB02 AB06 AC02 CA03 CA05 CB03 CB05 CC01 DA03

Claims (7)

[Claims] 1. A burner of an all-primary premix type, wherein combustion air is passed through the burner through a ventilation path, and the supplied fuel is mixed with the combustion air and supplied with the ventilation. A ventilation fan, a fuel supply path connected to the ventilation path so that suction force acts by the ventilation action of the ventilation fan, and a fuel supply path for supplying fuel; and a fuel supply path provided downstream of the installation location. A zero governor for maintaining the fuel supply pressure on the side at atmospheric pressure, and control means for controlling the combustion of the burner, wherein the control means has a ventilation amount corresponding to a combustion amount required in the combustion of the burner. A combustion device configured to adjust the rotation speed of the ventilation fan as described above, wherein the suction device is provided in a suction unit that sucks combustion air into the ventilation passage, and changes a passage resistance of the combustion air. By A combustion air supply amount adjusting unit that adjusts a combustion air supply amount to the ventilation path; and a combustion air supply amount adjustment unit that is provided at a downstream side of the zero governor in the fuel supply path and changes a fuel passage resistance. Fuel supply amount adjustment means for adjusting the fuel supply amount to the ventilation passage is provided, wherein the control means has a fuel passage resistance that is smaller in a region where the amount of combustion required in the combustion of the burner is smaller than in a region where the amount of combustion required is larger. The fuel supply amount adjusting means is adjusted so as to be larger, and the combustion resistance is set such that the combustion air passage resistance required for combustion of the burner is smaller than that of the larger region. Adjusting the air supply amount adjusting means, and irrespective of the adjustment of the combustion air supply amount adjusting means, to an appropriate ventilation amount corresponding to the combustion amount required in the combustion of the burner. Configured combustion apparatus so as to control the rotational speed of the ventilating fan so that. 2. The combustion apparatus according to claim 1, wherein the combustion air supply amount adjusting means is configured to adjust a passage area of the suction unit. 3. The combustion device according to claim 1, wherein the fuel supply amount adjusting means is configured to adjust a passage area of the fuel supply passage. 4. The fuel supply passage is branched into a plurality of fuel supply passage portions and connected to the ventilation passage, and the fuel supply amount adjusting means corresponds to all or a part of the plurality of fuel supply passage portions. 4. The fuel supply path according to claim 3, further comprising an electromagnetic on-off valve for opening and closing the installed fuel supply path portion, and adjusting the passage area of the fuel supply path by opening and closing the electromagnetic on-off valve. Combustion equipment. 5. The fuel supply amount adjusting means and the combustion air supply amount adjusting means are integrally formed.
The combustion device according to any one of claims 1 to 4. 6. The control device according to claim 1, wherein the control unit changes a target mixture ratio of fuel and combustion air in the ventilation passage according to a combustion amount required in combustion of the burner. 6. The combustion device according to any one of items 5 to 5. 7. The combustion device according to claim 1, wherein the fuel and the combustion air are mixed on the upstream side of the ventilation fan in the fuel supply direction.